This invention relates to a speed detecting device for marine propulsion units and more particularly to an improved arrangement for transmitting a speed signal from the lower unit of a marine drive to a remotely positioned speed indicator.
Various types of speed indicating devices are employed on watercraft. One of the most effective employs a pitot type of device having an opening that is disposed to the dynamic water pressure and which is connected by means of a passageway and interconnecting conduits to a remotely position speed detector and indicator. This type of device is particularly adapted for use with the lower unit of a marine outboard drive such as the outboard drive unit of an inboard/outboard drive or of an outboard motor per se. However, with such arrangements, it has been previously necessary to provide a series of passageways that extend through the lower unit and the upper unit and then to the remotely positioned speed indicating device. However, due to the relatively complex structure of the outboard drive, the formation of such passageways in the housings has presented several problems. In addition, when the upper unit is a part of the outboard drive of an inboard/outboard unit, the problem is complicated by the general construction of such units.
It is, therefore, a principal object of this invention to provide an improved speed detecting device for a marine propulsion unit.
It is a further object of this invention to provide an improved arrangement for transmitting the water pressure signal through the outboard drive to a remotely positioned indicator.
It is yet another object of this invention to provide a simple and easily formed passageway in the lower unit of a marine outboard drive and interconnecting conduit for connecting that passageway to the remotely positioned speed detector.